Devices and methods for identifying and monitoring changes of a suspect area of a patient

ABSTRACT

A device for acquiring first and subsequent images of a suspect area on a patient and methods for monitoring or detecting changes of the suspect area over time and providing notification when the changes exceed a threshold. The device may be an imaging device, such as a digital camera, possibly augmented with physical or optical devices for arranging the orientation and/or distance of the imaging device with respect to the suspect area. In addition, methods for identifying, relocating, acquiring a first and/or subsequent image of the suspect area, and performing a comparative analysis of respective images are also described. Results of the comparative analysis can be used to notify and/or assist a medical professional in treating or counseling patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/336,649, filed Jan. 19, 2006, now U.S. Pat. No. 7,657,101 issued Feb.2, 2010, which application claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application No. 60/645,538 filed Jan. 19, 2005,where these applications are incorporated herein by reference in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This disclosure relates to devices and methods, which can be used aloneor in combination, to identify and monitor changes of a suspect area ona patient, for example dermatological changes.

2. Description of the Related Art

There are many reasons why a medical professional, patient, or bothwould want to monitor changes on an exterior or internal surface of apatient. For a suspect area, especially one that may indicate some formof skin cancer, it is important to detect and treat the area in itsearly stages. One type of skin cancer is known as melanoma, which is amalignant cancer of the pigment cells (melanocytes). Other forms of skincancer also exist and are known as basal and squamous cell cancers,which are tumors of unpigmented cells (keratinocytes) of the skin.

Melanocytes occur at various depths within the epidermal (upper) anddermal (lower) layers of skin. Melanocytes are normally distributed inthe layers of the skin and produce pigment in response to beingsubjected to ultraviolet light (e.g., sunlight). Aggregated melanocytesare termed naevus cells and can be indicative of a melanoma. Because amelanoma may appear as a mole, medical professionals typically attemptto ascertain whether the suspicious area is changing over time.Identifying changes early typically results in a rapid diagnosis, whichin turn often leads to rapid and highly effective treatments that cangreatly increase the patient's survival rate and in most cases, completerecovery.

Historically, the standard of care for screening or monitoring melanomais a visual inspection or visual comparison of photographs by a medicalprofessional. These visual inspections or comparisons are subjective anddo not enable the medical professional to detect small or subtle changesin a suspect area. Changes in the perimeter, depth, shape, and evencolor of a melanoma can be subtle for a time and then progress rapidly.Moreover, changes in the color or perimeter, for example, of a melanomaare not easily discernable to the human eye so these changes may gounnoticed for a long period of time.

In U.S. Pat. No. 6,427,022, issued to Craine et al., a skin lesion ismonitored by obtaining a series of digital baseline images over time andcomparing these images. The method of comparison taught in Craine et al.is that the baseline image is compared visually by the viewer with asubsequently obtained image by alternately displaying the respectiveimages, in a blinking fashion. The blinking action is created by quicklyalternating the images with respect to one another on a display monitorto enable the viewer to detect changes in the skin lesion.

Even though the standards of care discussed above may involve images,each standard of care suffers from the subjectivity and uncertaintyassociated with the medical professional trying to ascertain changes ina suspicious area by visual comparison. The visual comparison methodsare subjective and less accurate for a number of reasons. For instance,the medical professional may be inexperienced, may have been distractedduring the examination, or may have selected the wrong location on thepatient's body during a follow-up examination.

Therefore, a more effective, less subjective, and low-cost approach forat least monitoring changes in a suspect area is desirable.

SUMMARY OF THE INVENTION

It should be understood that one aspect of the present invention is thecomparison of a plurality (e.g., at least two) images taken at differenttimes utilizing a computer based algorithm that can overlay two imagesand either transform the images to fit over each other or do a best fitanalysis thereby denoting or calling out one or more of any color,perimeter, or depth changes. In one embodiment the analysis can includetransforming the images to match color, contrast, angle, focus(sharpness), brightness, and subsequently comparing the multiple imageswith each other. Changes between the images may be called out in avariety of ways. Such embodiments include text reports, highlight orcolor coding the image itself, etc.

In another aspect a device or apparatus is contemplated that comprises adigital image capture device and a distance-measuring device. In certainembodiments the distance measuring device measures the distance betweenthe suspect area and the image capture device and provides a read-out ora tone to signify the optimal distance. Further, embodiments include theuse of a reference such as a strip of adhesive affixed to the surface orattached the device that provide contrast, color, sharpness, and/ordepth references. Such an embodiment could include an adhesive striphaving a color palette (e.g., one or more colors), gray scale, distancereferences (hash marks) or depth references.

In certain embodiments of the invention distance measurements can bedone by a sonic device, laser or any other means of measuring distance.

In one particular embodiment an enclosed tube or housing is affixed tothe image device and positioned over the suspect area. In one embodimentof such a device the housing or enclosure is essentially light free andmay contain its own light source internally to provide consistentlighting of the suspect area. In a specific embodiment the enclosure isa tube of a fixed length have LEDs or fiber optics positioned inside.One end of such an enclosure may be fitted to the image capturing deviceand the other fitted over the suspect area.

In one aspect, an apparatus to acquire an image of a suspect area on apatient comprises an imaging device; and a separation tool having afirst end connected with a first section, at least a portion of thefirst end formed to contact the patient, the first section having anattachment portion to receive the imaging device, the first sectionformed to maintain the imaging device at a substantially fixed distancefrom the suspect area.

In another aspect, an imaging assembly to image a suspect area on apatient comprises an imaging device and at least one sensor to indicatean orientation and/or distance of the imaging device relative to a firstlocation.

In another aspect, an imaging assembly to image a suspect area on apatient comprises a housing; an imaging device located within thehousing; and at least one sensor to indicate an orientation of thehousing relative to a first location.

In yet another aspect, a method of acquiring an image of a suspect areaincludes identifying the suspect area; positioning a patient with thesuspect area in approximately a first position; identifying a referenceitem located on the patient; determining a position of the suspect areain relationship to the reference item; aligning an imaging device toacquire the image of the suspect area; and acquiring the image afteraligning the image device.

In yet another aspect, a method of comparing at least two images, eachimage capturing a suspect area includes identifying a reference item inthe at least two images; measuring an attribute of the reference item ina first image; transforming a second image based on the measuredattribute of the reference item in the first image, wherein a referenceitem in the second image is transformed to correspond with anorientation and size of the reference item in the first image; measuringan attribute of the suspect areas in both images; and comparing therespective measured attributes of the respective suspect areas. Suchreference items can be points either away from the suspect area orwithin the suspect area. Further, the measured attribute can be color,distance between at least two points, total perimeter, distance betweenmultiple points etc.

In one aspect the method of comparing two images comprises receiving atleast two images digitally into a computer system, performing a fittinganalysis on the at least two images to obtain an overlay and providingan output noting any differences between the at least two images.

In yet another aspect, a method of acquiring an image of a suspect areaincludes identifying the suspect area; positioning a patient with thesuspect area in approximately a first position; aligning an imagingdevice to acquire an image of the suspect area; and acquiring the imageafter aligning the image device.

In still yet another aspect, a method of comparing at least two imagesof a suspect area on a patient includes providing at least two digitalimages of the suspect area; digitally overlaying the at least twoimages; performing a best-fit transformation of one image to encouragethe one image to approximately correspond to at least one detectedattribute of the other acquired image; comparing the at least two imagesto determine whether a difference exists between an aspect of the oneimage when compared with the same aspect of the other image.

In an even further aspect the present invention can be used in thecontext of full-body imaging wherein one or more digital or other imagecapture device or devices are placed around the patient and thefull-body is imaged either in a piece by piece manner or in itsentirety. These images can then be compared by transformation orbest-fit analysis and analyzed for any changes by a computer algorithm.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn, are notintended to convey any information regarding the actual shape of theparticular elements, and have been solely selected for ease ofrecognition in the drawings.

FIG. 1A is a front, left isometric view of an imaging device accordingto one illustrated embodiment positioned with respect to a portion ofskin.

FIG. 1B is a side view of a portion of a guide of the imaging device ofFIG. 1A having measurement markers and a palette according to oneillustrated embodiment.

FIG. 2A is a partially exploded, front, left, isometric view of animaging device according to another illustrated embodiment.

FIG. 2B is a front, left isometric view of an intermediate bracketaccording to one illustrated embodiment.

FIG. 3 is a front, left, isometric view of an imaging device accordingto another illustrated embodiment.

FIG. 4 is an elevational view of a hand having several reference pointsfor locating a suspect area according to one illustrated embodiment.

FIG. 5A is a flowchart of a method of identifying a suspect areaaccording to one illustrated embodiment.

FIG. 5B is a continuation of the flowchart of FIG. 5A.

FIG. 6 is a top plan view of an image after the image has beenpre-processed according to one illustrated embodiment.

FIG. 7 is a flowchart of a method of acquiring a subsequent image of asuspect area according to one illustrated embodiment.

FIG. 8A is left, front isometric view of a first image and a secondimage, each having in an initial and respectively different orientationand size according to one illustrated embodiment.

FIG. 8B is a top plan view of the first image and the second image ofFIG. 8A transformed to have approximately the same respectiveorientation and size.

FIG. 9 is a flowchart of a method of comparing at least two images of asuspect area according to one illustrated embodiment.

FIGS. 10A-10C are images of suspect areas illustrating the variousstages of the color balancing method of FIG. 11 according to oneillustrated embodiment.

FIG. 11 is a flowchart of a method of color balancing an image to detecta potential suspect area according to one illustrated embodiment.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments of thedisclosed subject matter. However, one skilled in the art willunderstand that the embodiments may be practiced without these details.In other instances, well-known structures associated with imagingsystems, computing systems and processors, and various techniques formanipulating and evaluating digital image data have not been shown ordescribed in detail to avoid unnecessarily obscuring descriptions of theembodiments.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is as “including, but not limited to.”

Unless the context requires otherwise, throughout the specification andclaims that follow, the term “patient” refers primarily to warm bloodedmammals and is not limited to human beings, but could include animalssuch as dogs, cats, horses, cows, pigs, higher and lower primates, etc.

The headings provided herein are for convenience only and do notinterpret the scope or meaning of the claimed invention.

The embodiments disclosed herein are generally directed to acquiringimages of a suspect area located on a patient, comparing the acquiredimages to one another; and evaluating the compared images to determineif some amount of change from one image to a subsequent image warrants amore detailed examination by a medical care professional. Theembodiments disclose a number of different devices and methods forachieving such results.

The surface of interest can be either internal or external to thepatient. In one instance, the surface of interest is the patient'sexposed skin that is monitored for the detection or growth of skincancer. In another instance, the surface of interest can be thepatient's mucous membranes, interior body surfaces related toreproductive and/or digestive systems of the patient, ocular surfaces,or any other accessible surface on a patient. For purposes of thisdescription, the surface of interest will be exemplified as an area onthe patient's skin, referred to as a suspect area. However, thisexemplification is not meant to limit or otherwise narrow the scope ofthe description, the claims, or any specific embodiment depicted herein.

The suspect area referred to herein can be the site of a suspectedmelanoma or mole (e.g., melanin containing areas to be monitored), butcan also be any other suspect area on a patient that needs to bemonitored. Thus, it is within the scope of this disclosure that thesuspect area can be located in a variety of places on a patient, forexample the patient's mucous membranes, surfaces of interior bodycavities related to reproductive and/or digestive systems, ocularsurfaces, or any other interior or exterior surface on a patient wheremonitoring is desired. In the exemplary embodiment used for discussionpurposes, the suspect area can be a dermal feature, such a type of skincancer, a skin lesion, a skin rash, a burn or scar, an infected orinflamed area, a wound, or some other skin anomaly that may or may notbe capable of growth, reduction or other change. For example, oneembodiment may monitor a healing rate (i.e., recession) of a burn orscar when certain medications, lotions, or creams are applied to theskin. A further embodiment envisions utilizing such technology tomonitor the effectiveness of a drug or nutriceutical, such as those thatheal the skin. Another embodiment may monitor a patient's scalp for hairloss and/or growth. In addition, the embodiments disclosed herein may beused in a number of settings, such as a home setting, a clinicalsetting, a laboratory or research setting, a regulatory compliancesetting, or any combination of the above.

Devices and Systems to Acquire an Image of a Suspect Area

FIGS. 1A-3 show three different embodiments of a device to acquire animage of a suspect area. Each of the devices differs in its degree ofcomplexity, accuracy, and cost. It is contemplated that many, if notall, of the features or aspects of one device can be incorporated intothe other devices.

FIG. 1A shows a first imaging device 10 for imaging a suspect area 12 onskin 14 according to the illustrated embodiment. The first imagingdevice 10 includes a housing 16 and a lens 18 to receive and directlight to imaging components (not shown) located within the housing 16.By locating the imaging components in the housing 16, damage and/orexposure of the imaging components may be prevented. The housing 16 canhave a handle 20 to permit the housing 16 to be lifted, moved,positioned, or otherwise manipulated. Additionally or alternatively, thehandle 20 and/or other portions of the housing 16 can be configured withsupport locations so that the imaging device 10 can be secured to atripod, for example.

The imaging components may take the form of a camera or an opticalscanner operable to capture images of the suspect area 12. In oneembodiment, the camera may advantageously take the form of a digitalimage capture device such as a CCD or CMOS type camera. A CCD camera mayconsist of one-dimensional or two-dimensional arrays of charge coupleddevices (“CCD”) and suitable optics, such as optical lenses, forfocusing an image on the CCD array. CCD arrays can capture whole imagesat a time, or can be electronically controlled to successively sample(e.g., pixel-by-pixel, row-by-row, or column-by-column) the informationon a region of the skin 14 (i.e., electronically scan). Alternatively,the imaging components can take the form of a CMOS imager capable ofcapturing one-dimensional or two-dimensional arrays similar to that of aCCD reader.

Employing a digital image capture device advantageously provides theimage in a form suitable for use with a data processing system such as acomputing system. Alternatively, the camera may take the form of anon-digital image capture device, such as a film camera. Suchembodiments may employ image scanners, or other devices to digitize theimages captured on film. The imaging device 10 may advantageously takethe form of a still image capture device. Alternatively, the imagingdevice 10 may take the form of a motion picture capture device such as amovie camera or video camera. Such embodiments may include a framegrabber or other device to capture single images.

The imaging device 10 may rely on ambient light, or may include one ormore light sources, such as light emitting diodes (“LEDs”) orincandescent lights, which may be manually or automatically controlled.

A guide 22 is attachable to the housing 16 of the imaging device 10. Theguide 22 is configured so that the housing 16 can be placed at a desireddistance away from the skin 14 along a Z-axis, perpendicular to an X-Yplane when an image is acquired. In the illustrated embodiment, theguide 22 includes an extension member 24 having a first end 26 that iscoupled to the housing 16 of the imaging device 10. A second end 28 iscoupled to a contact member 30. The contact member 30 can include anumber of features to enhance the control and/or optimization of theimaging device 10. For example as illustrated in FIG. 1B, the contactmember 30 of the guide 22 can include measurement markings 30 a, similarto those of a ruler, and/or contrast markings 30 b, which can representa color or grayscale palette.

In one embodiment, the extension member 24 includes adjustable,complementary sliding members with gradations 25 to allow the housing 16to be placed at a desired distance from the suspect area 12. In anotherembodiment, the extension member 24 is formed to be non-adjustable, thusthe housing 16 is set at a fixed length from the contact member 30. Thecontact member 30 may be shaped (e.g., arc-shaped) to provide anunobstructed line of sight between the imaging device 10 and the suspectarea 12. As will be discussed in more detail below, it may be desirablethat the contact member 30 be shaped such that at least a portion of thecontact member 30 can be captured in the acquired image. A skin contactregion 31 of the contact member 30 can be padded to provide a morecomfortable interaction with the patient. One skilled in the art willunderstand and appreciate that the first end 26 can be coupled to thehousing 16 by any number of mechanical methods, for example fasteners,clips, VELCRO®, adhesive bonding, tie down straps, or some otherstructure that substantially keeps the housing 16 attached to theextension member 24.

In the illustrated embodiment, the imaging device 10 can include atleast one sensor 32 for determining an orientation of the device 10. Oneadvantage of determining the orientation of the device 10 is to providefor repetitive and consistent images in an X-Y plane, especially if theimages are acquired at different times. For example, if a second imageis being acquired of the suspect area 12, but the imaging device 10 istilted or rotated at too much of an angle, the second image may be toodistorted or misaligned to digitally process or compare to a previouslyacquired image.

A variety of sensors 32 can be used to indicate the orientation of theimaging device 10. In the illustrated embodiments, the sensor 32 is afluid level encompassed in the housing 16 and visible by a user of theimaging device 10. The sensor 32 may also be integrated with the guide22. The fluid level sensor 32 generally indicates whether the imagingdevice 10 is tilted relative to the ground. Additionally oralternatively, a gyroscope, which is sometimes referred to as a tiltsensor, can be used to determine an acceleration of the imaging device10 about at least one axis.

In addition to or instead of sensing the orientation of the imagingdevice 10, other sensors 34 can be used to determine the proximity ofthe imaging device 10 in relation to the skin 14 of the patient. In oneembodiment, a pressure sensor 34 is located in the contact member 30 tosense the pressure exerted on the contact member 30 as it is positionedagainst the skin 14 of the patient. By sensing the pressure that theimaging device 10 is pressed against the skin 14, the imaging device 10can be repetitively and accurately repositioned relative to the suspectarea 12 from one image to the next. Additionally or alternatively, aproximity sensor 35 can be used to detect when the contact member 30 isat a desired distance from the patient, to include when the contactmember 30 barely makes contact with the patient.

Each of the sensors 32, 34, and/or 35, described above, as well asequivalent sensors, can be electronically coupled with the imagingdevice 10 to provide an indication that the imaging device 10 is at thedesired orientation or distance. For example, the imaging device 10 canhave an indicator 36 that sends a visual and/or audio signal to indicatewhen the imaging device 10 is at the desired orientation, distance,and/or when an amount of pressure is present between the contact member30 and the patient. A signal from the indicator 36 would indicate thatthe image could be acquired at that moment in time. Likewise, thesensors 32, 34, and/or 35 can also be electronically coupled with aprocessor (not shown) to computationally update the orientation and/orproximity to the patient of the imaging device 10. In one embodiment,the processed information can be displayed on a screen (not shown)located on the housing 16.

FIG. 2A shows a second imaging device 100 that includes a camera 102 anda member 104 for receiving and coupling the camera 102 to an extensionmember 106. Similar to the extension member discussed above, theextension member 106 includes a contact member 108. In addition, theextension member 106 further includes detents 110 sized and configuredto complementarily receive the member 104, a sensor 112 to indicate theorientation of the extension member 106 about a Roll axis 114, a Pitchaxis 116, and/or a Yaw axis 118, and a color palette 120 that can beused to provide color and/or contrast balancing once the image isacquired and archived. Color and/or contrast balancing are described inmore detail below.

The camera 102 can be a digital camera as described in the previousembodiment or a film camera that includes at least a lens 122, a camerabody 124, an image trigger 126. The camera can capture images onphotographic film (not shown), which can be standard photographic filmthat is purchased in a store and is configured to be chemicallyprocessed in a photo lab after it has been exposed to light.Alternatively, the photographic film may be specialized film, such asfilm that is sensitive to the non-visible portions of theelectromagnetic spectrum, such as infrared or ultraviolet sensitivefilms.

In the illustrated embodiment, the member 104 includes a compartment 128that is sized to receive the camera 102 and a pair of flanges 130 formedto couple to the extension member 106. A front portion 128 of thecompartment 128 does not obstruct the lens 122 of the camera 102 whenthe camera 102 is seated in the compartment 128. The camera 102 can besecured to the member 104 by virtue of the compartment 128 being sizedto provide a tight or snug fit for the camera body 124. Alternatively,hook and loop fastener pads, commonly available under the trademarkVELCRO®, can be provided to keep the camera 102 relatively secure in thecompartment 128. One skilled in the art will appreciate and understandthat securing the camera 102 in the compartment 128 can be accomplishedin a variety of known ways.

The flanges 130 are further formed to complementarily engage the detents110 provided on the extension member 106. In the illustrated embodiment,the flanges 130 include rounded, depressible buttons 132. Sliding afirst end 134 of the extension member 106 in between the flanges 130 andpermitting the buttons 132 to click into the detents 110, so that thecontact member 108 is at a desired distance from the camera 102,accomplishes the assembly of the member 104 with the extension member106.

FIG. 2B shows a different embodiment of a member 104 without acompartment. Instead, a bonding strip 136 is provided on a base 138 ofthe member 104. Each side 140, extending from the base 138 can be biaslyresilient to form a snug fit with the camera 102. The bonding strip 136can be a pad of hook and loop fastener, a tacky substance, or otherequivalent object or substance.

FIG. 3 shows an automated imaging device 200 according to anotherembodiment. Many of the aspects of the imaging device 200 are similar tothe aspects described in the previous embodiments, for example a housing202, an imager 204, a handle 206, and a sensor 208. One differencebetween the imaging device 200 and the previously described devices 10,100 is that the present embodiment does not employ an extension member.In lieu of the extension member, a second sensor or range finder 210 isused to indicate the distance between the imaging device 204 and asuspect area 212.

In one embodiment, the range finder 210 is a laser triangulation sensorthat provides non-contact linear displacement measurements of thesuspect area 212 on the skin 214. A laser beam (e.g., from asemiconductor laser) is reflected off the skin 214. A returning beam isreceived and focused onto a CCD sensing array (not shown) of the imager204. The CCD array detects the peak value of the light and determinesthe distance of the skin 214 based on the position of the beam spot. Therange finder 210 produces an analog voltage that is proportional to thedistance of the skin 214 from the range finder 210.

As an alternative to the above embodiment, the range finder 210 can be alaser interferometer, an ultrasonic sensor, or an equivalent sensor tomeasure the linear distance of the dermal suspect 212 to the rangefinder 210. Laser interferometers use the length of a wave of light asthe unit for measuring position and consist of three basic components, alaser that supplies a monochromatic light beam, optics that direct thebeam and generate an interference pattern, and electronics which detectand count the light and dark interference fringes and output thedistance information. Ultrasonic sensors offer another means to makenon-contact distance measurements. An ultrasonic sensor works bymeasuring the time it takes a sound wave to propagate from the rangefinder 210, to an object and back to the range finder 210. In theillustrated embodiment, the skin 214 would reflect the ultrasonic wavesgenerated by a transmitter and then a receiver would detect thereturning waves. The elapsed time from initial transmission to receptionof the returning waves is used to determine the distance to the skin214.

The monochromatic light used to illuminate at least the suspect area 212during imaging can have a wavelength outside of the visible portion ofthe light spectrum. For example, the monochromatic light can be in afrequency range of ultraviolet light, infrared light, or some othernon-visible range along the light spectrum.

In yet another embodiment, the imaging device 200 is a camera. Again,the imaging device 200 may advantageously take the form of a still imagecapture device, a motion picture capture device such as a movie cameraor video camera. In the present embodiment, the alignment of the imagingdevice 200 is accomplished manually without the aid of an extensionmember or sensor. The acquired images are compared in a best-fitanalysis. The best-fit analysis includes digitizing the images andmatching key points or parameters of a first image onto similar keypoints or parameters of a second image. For example, the perimeter orborder of the first image can be matched to the perimeter or border ofthe second image. It is appreciated that in one embodiment the firstimage and the second image are of the same suspect area and the best-fitanalysis is employed to detect changes, if any, of the suspect area overtime without respect to using other reference points and/or markers toalign and/or orient the imaging device 200 relative to the suspect area.The analysis software can transform, rotate, and otherwise manipulate atleast one of the images until enough similarities are found between thetwo compared images to verify that both images are of the same suspectarea or are possibly not of the same suspect area. The best-fit analysisis described in more detail below in the discussion on image comparison.

Devices and Systems to Acquire Images of Larger Surfaces

In one embodiment, a system is capable of contemporaneously acquiringimages over a variety of locations on a patient. The system can captureimages over a larger surface area or can take multiple images over alarger area where the multiple images can be digitally overlaid andmatched to form a large image.

Methods of Identifying and Re-Locating a Suspect Area

FIG. 4 shows a patient's hand 300 according to one embodiment. By way ofexample, a suspect area 302 (e.g., a grouping of melanoma cells) appearson a backside surface 304 of the patient's hand 300. Two spots areidentifiable on the backside surface 304, a first spot 306 (e.g., ascar) is located on the ring finger 308 and a second spot 310 (e.g., afreckle) is located on the wrist 312 of the patient's hand 300. Thespots 306, 310, respectively, can be freckles, birthmarks, borders of alimb, or some other equivalent feature or landmark that is notsusceptible to substantial changes in shape, size, and/or location withrespect to its present location on the patient. Further, the spot 306 or310 may be naturally occurring, such as a freckle, or the spot 306 or310 may be a portion of a scar, a tattoo, or some other feature that isnot susceptible to substantial changes in shape, size, and/or locationwith respect its present location on the patient.

One advantage of locating at least one of the spots 306 or 310 on thepatient is to use one of the spots 306 or 310 as a reference object 311.The reference object 311, which is equivalent to spot 310 in theillustrated embodiment, provides a starting point from which other keymeasurements can be taken, as explained in the method below. However, itis appreciated that a reference object 311 is not always necessary whenthe suspect area can be easily relocated. For example, a group ofmelanoma cells that is easily and routinely detectable on a patientcould be imaged and re-imaged, especially when the images are comparedusing a best-fit analysis.

The selection of the spots 306, 310 is generally left to the discretionof the medical professional, and it is contemplated that the medicalprofessional will select the spot 310 that is the most stable or lesssusceptible to change over time. Optionally, the imaging software mayalso select the spots 306, 310. Although the first spot 306 may have astable configuration, such as the scar, the location of the spot 306 onthe ring finger 308 makes it less attractive as an reference object 311because the ring finger 308 is easily moveable in relation to the hand300, which can add error in repetitive measurements taken with respectto the spot 306 on the ring finger 308. In contrast, the second spot310, shown on the wrist 312, has a more fixed relationship with respectto the suspect area 302 and thus may be a better reference object 311from which to measure and document the location of the suspect area 302.

It is also advantageous if the reference object 311 or at least areference marker 318 is located proximate to the suspect area 302 sothat the reference object 311 or reference marker 318 can be captured inan image of the suspect area 302. In accordance with the embodimentsherein and described in more detail below, it is desirable to manipulatean image by matching or overlaying either the reference objects 311 orreference markers 318 that appear in different images, taken atdifferent times. In the illustrated embodiment, the reference marker 318has a defined size and shape and can be placed quite near the suspectarea 302. The advantage, however, of locating the reference object 311remains unchanged because the placement of the reference marker 318 onthe patient is made relative to the location of the reference object 311on the patient.

Methods of Acquiring a First Image of a Suspect Area

FIG. 5 is a flowchart illustrating a method 400 to identify and take animage of a suspect area 302 on a patient. For clarity and ease ofexplanation, the method 400 is described in reference to FIG. 4. Oneaspect of locating the suspect area 302 is to accurately identify, map,and document the reference object 311, the marker 318, if needed, andthe suspect area 302 for image comparison purposes as described ingreater detail below.

FIG. 5 shows that the method 400 commences at 402 where the suspect areais identified on the patient. A medical professional, the patient, thecomputing system, or some other entity may identify the suspect area.Identifying the suspect area most often will be done visually, but it isunderstood that other approaches may be used, such as the sense oftouch.

At 404, a reference object is identified on the patient. At 406, themedical professional determines whether the reference object will bewithin a first field-of-view or first frame 314 (FIG. 4) of an imagingdevice. Recall, it is desirable to have the reference object 311 withinthe first frame 314 of because multiple images of the suspect area 302will be compared to one another. In one embodiment, the first frame 314is sized to provide an amount of resolution of the suspect area 302 thatwill be adequate for detailed image processing and evaluation.

If the reference object 311 is advantageously within the first frame 314of the imaging device, then at 408, a position of the suspect area 302is determined relative to the reference object 311. In one embodiment, aCartesian coordinate system (X, Y) having perpendicular axes, is used todetermine the position of the suspect area 302 relative to the referenceobject 311. In another embodiment, a spherical coordinate system (r, θ)is used. By way of the exemplary embodiment illustrated in FIG. 4, whichemploys the Cartesian coordinate system, the reference object 311 isassigned coordinates “0, 0” and the suspect area 302, as measured fromthe reference object 311, is determined to have coordinates of (a, b) ata point on the suspect area 302 that represents an approximate centerpoint of the suspect area 302. If a smaller image frame 316 (FIG. 4) isnecessary, for example to get an image with higher resolution, and thereference object 311 is located outside of the smaller image frame 316,then at 410, the reference marker 318 (FIG. 4) is placed in proximity tothe suspect area 302. At 412, a position of the reference marker 318 isdetermined relative to the reference object 311, for example theposition of the reference marker 318 is determined to have coordinates(c, d). Next, the position of the suspect area 302 is determinedrelative to the reference marker 318 and, by way of example, hascoordinates (e, f).

In one embodiment, the reference marker 318 is a pen mark on thepatient. In another embodiment, the reference marker 318 is a smallpatch or sticker backed with an adhesive. The shape of the patch iscustomized so that the reference marker 318 can be placed in a desiredorientation during successive examinations of the patient. In theillustrated embodiment of FIG. 4, the reference marker 318 includes apointed region that points towards the finger tips and parallel sidesthat substantially align with the sides of the patient's arm. Oneskilled in the art will understand and appreciate that the referencemarker 311 can have a variety of shapes, sizes, colors, contrastfeatures, textures, and can even have features, like a center dot, toidentify an exact starting point for measurements. Additionally oralternatively, human-readable and/or machine-readable indicia can beencoded on the reference marker 318.

It should be understood that in certain aspects of the invention noreference object is utilized per se, and the computer algorithm performsbest fit on two images using only the suspect area or multiple pointswithin the picture frame to make a transformation or best fit analysis.While user applied reference markers or the use of anatomical featuresas reference points are useful and may lead to higher quality results incertain scenarios, they are by no means required and thus should beconsidered optional embodiments. In addition, when utilizing suchanalysis in certain embodiments a computer algorithm can take points onthe perimeter of the lesion or suspect area of a first image and performmultiple measurements between any two points or more and compare suchmeasurements with a second image. The first and second image may beresized, skewed, color balanced and/or brightness changed to assist inattempting to fit one image to the other. When measurements betweenpoints in the first image and measurements between points in the secondimage are substantially the same the images can be considered comparedand any deviations outside the error for such comparisons can be notedas a possible change for the user or medical professional to review.

The coordinates of the reference object 311, the reference marker 318,if needed, and the suspect area 302 can be recorded and/or documented onpaper or via and electronic medium, for example entering the data into acomputer. In addition, descriptions of these features can also berecorded and/or documented. It is understood that the recordation and/ordocumentation can be accomplished in a number of known ways, which maybe through manual, automatic, paper, or paperless means. At 414, animaging device 10, 100, 200 is positioned to take an image of thesuspect area 302. Because the images will be digitally processed, it isdesirable to position the imaging device 10, 100, 200 in a repeatablemanner with respect to the suspect area 302. Depending on the type ofmethod used to compare images and the quality of the images, it maydesirable that the distance of the imaging device 10, 100, 200 from andthe angle of the imaging device 10, 100, 200 with respect to the suspectarea 302 is kept substantially constant from one image to the next.However, it is appreciated and understood that the distance and angle ofthe imaging device 10, 100, 200 with respect to the suspect area 302 canvary by a significant amount from one image to the next and theanalysis/comparison software can best-fit analysis to substantiallymatch and align respective images. In addition, it may also be desirableto maintain constant lighting, at least within the frame of the image,in order to more easily detect color changes and/or shape changes of thesuspect area 302 when the images are electronically processed andcompared.

In another embodiment, the imaging device 10, 100, 200 can include astereo camera to add depth perception to the resulting image. Stereocameras that are placed at a constant distance from each other couldprovide two images, one from each camera, of the suspect area 302. Whenthe images are compared against each other, the depth and/or texture ofthe suspect area 302 can be determined.

Optionally, at 416, a parameter on the imaging device 10, 100, 200 maybe adjusted to enhance a quality of the image. For example, lightfilters or color filters can be coupled with the imaging device 10, 100,200 as a way to control the light within the frame of the image.Additionally or alternatively, the imaging device 10, 100, 200 can befocused to obtain a desired resolution, thus increasing or decreasingthe frame size of the image to be acquired.

At 418, a first image is acquired that captures the suspect area 302alone or the suspect area with one of either the reference object 311 orthe reference marker 318. At 420, the first image is electronicallyarchived. During the archiving process, the first image can be given anidentifier such as a file name, label, number, date stamp, or some otherassociation that makes it easy to re-locate the first image in adatabase. The electronic format of the first image can be archived asany number of common graphics formats such as *.jpg, *.tif, *.bmp,*.gif, or another equivalent format that is readable by a standardcomputer system.

Optionally, at 422, the first image may be preprocessed. Pre-processingthe first image may include, but is not limited to, identifying thereference object 311 and/or reference marker 318 in the image;detecting, mapping, and computing the border of the object 311 and/ormarker 318; detecting, mapping, and computing the border of the suspectarea 302; and/or overlaying a reference grid 608 onto the image as shownin FIG. 6, according to one illustrated, exemplary embodiment.

FIG. 6 shows an image 600 having an image frame 602. Captured within theimage frame 602 is an image 604 (i.e., an image of the suspect area 302)and a reference image 606 (i.e., an image of either one of the referenceobject 311 or the reference marker 318) located nearby or within image604. The reference grid 608 overlies the image 604 and the referenceimage 606. One advantage of including the reference grid 608 is that thegrid 608 can be printed with the image 600. This allows the medicalprofessional to more easily visually examine the image 604 to identifyobvious changes. Another advantage of the reference grid 608 is that itallows the medical professional to more accurately identify, describe,and even communicate respective changes of the suspect area 302 byreferring to various quadrants or blocks of the reference grid, whichcan be colored or coded to indicate regions where substantial change hasoccurred.

Methods of Acquiring a Subsequent Image of a Suspect Area

FIG. 7 shows a method 700 of acquiring a subsequent image of the suspectarea 302 according to one embodiment. Method 700 differs from theprevious method 400 in that method 700 includes relocating the suspectarea 302 and realigning the imaging device 10, 100, 200. At 702, thesuspect area 302 is relocated on the patient. As explained above, one ofthe purposes of the embodiments described herein is to track the changesof a suspect area 302. Because some patients may have many suspiciousareas that are crowded together in one location or suspicious areas thatrapidly change, it is important to relocate the exact area that is to bere-evaluated.

The suspect area 302 can be relocated by visually inspecting thepatient, reviewing the patient's records, reviewing the position of adocumented reference object and then measuring to obtain the position ofthe suspect area 302, automated by the computing system, or somecombination thereof. At 704, a reference marker 318 can be repositionedon the patient proximate to the suspect area 302, if necessary.

The patient is positioned at 706 and an imaging device 10, 100, 200 isreoriented and/or realigned relative to the suspect area 302. Recallthat a distance and an angle of the imaging device 10, 100, 200 used toacquire a subsequent image should be approximately matched to a distanceand an angle of the imaging device 10, 100, 200 of a previous image. Theorientation of the imaging device 10, 100, 200 does not have to exactlymatch because a transformation algorithm can be used to account for someamount of deviation in the angle, the distance, and even the lighting.At 708, a parameter (e.g., functional features such as zoom, contrast,etc.) on the imaging device 10, 100, 200 may be adjusted to enhance aquality of the image, if necessary.

At 710, a subsequent image is acquired that captures both the suspectarea 302 and one of either the reference object 311 or the referencemarker 318. At 712, the subsequent image is electronically archivedaccording to the archiving process described above. Optionally, at 714,the subsequent image may be pre-processed as described above andillustrated in FIG. 6.

Image Transformation

FIG. 8A shows two images 600 a, 600 b undergoing a transformationaccording to one embodiment. A first image 600 a includes a first frame602 a enclosing a first reference image 606 a and a first image 604 a.The orientation of the first frame 602 a results from the angle andposition of the imaging device 10, 100, 200 when the image was acquired.A second image 600 b includes a second frame 602 b enclosing a secondreference image 606 b and a second image 604 b, wherein both the firstimage 604 a and the second image 604 b are images of the suspect area302. It should be understood the second reference image 600 b may beskewed, of a different size, or otherwise misaligned with respect to thefirst reference image 600 a. Thus, the transformation algorithm is usedto align, size, deskew, or otherwise manipulate the second referenceimage 606 b to match the first reference image 606 a as closely aspossible. Moreover, any changes made to the second reference image 606 bduring the transformation process are made to the entire image 600 b andeverything enclosed within the image 606 b. For example, if thereference image 606 b is scaled down by ten percent, then the secondframe 602 b, the reference grid (not shown for clarity), and the secondimage 604 b are also scaled down by ten percent. Further it should benoted that reference image 606 a and 606 b need not be separate fromimages 604 a and 604 b, but can be points within or on images 604 a and604 b that are considered by the computer algorithm during the fitanalysis.

FIG. 8B shows the same two images from FIG. 8A about to be overlaidafter the second image 600 b has been transformed. Once the images 600a, 600 b are overlaid with respect to one another, a comparisonalgorithm can be employed to detect, map, and document differences, ifany, between the first image 604 a and the second image 604 b.

Methods of Comparing Images

FIG. 9 shows a method 800 to compare subsequent images 600 a, 600 btaken of a suspect area 302 according to one illustrated embodiment.This comparison can take place in a variety of settings, for example inthe facility where the patient is treated or in a remote facility. Thecomparison, when done remotely, simply means that images of the suspectarea 302 are forwarded to another location, which could be by a computeralgorithm or a third party technician that specializes in performing theimage comparisons. The images can be transferred to the remote facilitythrough any available means, for example over a computer network(private or the Internet), through a file transfer protocol (FTP)system, by courier or regular mail, with the images stored on a computerreadable medium such as a compact disk, magnetic storage device, orother equivalent digital storage media.

The method 800 can commence with the first image 600 a being compared toa second, subsequent image 600 b, for example. In the presentembodiment, the images have been electronically archived, but they maynot have been pre-processed. In addition, the present embodiment is notlimited to the comparison of only two images. It is appreciated andunderstood that multiple images can be simultaneously compared against abaseline image and/or relative to each other. For example, each imagetaken over the preceding six months could be simultaneously compared toa first image 600 a taken the previous year. In one embodiment, ananimation software program can be used to animate the changes in thesuspect area 302 over time. For purposes of clarity and brevity,however, the comparison of only two images will be described below.

At 802, the electronically archived images are accessed from a databaseof images. At 804, the images are pre-processed, if desired. Optionally,at 806 a user may select a baseline image 600 a. The baseline imagecould be a first acquired image, an intermediately acquired image, or animage taken during the patient's previous office visit. For purposes ofdetecting changes, it is not necessary, but may be helpful to select abaseline image.

At 808, a mapping algorithm can be used to determine key features, suchas a border or perimeter of the reference images 606 a, 606 b.Alternatively, a mapping algorithm may look for key points on thereference images 606 a, 606 b with respect to the reference grid 608(FIG. 6) or may use reference images 606 a and 606 b as points on images604 a and 604 b during the fit analysis. In all of the embodimentsdescribed herein reference images 606 a and 606 b should be understoodto be an image such as a landmark feature on the surface or simply areference point or pixel or collection of pixels either separated fromimages 604 a and 604 b or on or within 604 a or 604 b. Thus, the termimage should be construed to mean a point that can be captured in adigital form and used as a reference point.

At 810, a transformation algorithm is used to transform the second image600 b into a comparative posture with the first image 600 a by using thereference images 606 a, 600 b. In one embodiment, the reference image600 b is scaled up or down in size, rotated, skewed, or otherwisemanipulated so that the reference images 606 b is approximately the samesize, same orientation, and in the same position within the frame 602 bas the first reference image 606 a of frame 602 a. In an alternateembodiment, both images 600 a, 600 b can be scaled up or down in size,rotated, skewed, or otherwise manipulated so that the respectivereference images 606 a, 606 b are approximately the same size, have thesame orientation, and are in the same position with respect to thereference grid 608 (FIG. 6). It should be understood that in certainaspects the reference images 606 a and 606 b are in fact containedwithin images 604 a and 604 b. Such reference images may correspond topoints on the perimeter of images 604 a and 604 b that appear unchangedonce the images are sized and overlaid. As one of ordinary skill in theart can readily appreciate the more reference points taken into accountduring the fit analysis, the higher the quality of the comparison.Accordingly, in certain embodiments at least two reference points areconsidered, in other embodiments, at least 3, 4, 5, 6, 7, 8, 9, 10, 15,20, or more are utilized by the algorithm.

At 812, after the reference images 606 a, 606 b have been sufficientlymatched during the transformation process; a comparison algorithm isused to evaluate and compare the respective images 604 a, 604 b. Keypoints or parameters are identified in both the first image 604 a andthe second image 604 b. For example, the overall area, the perimeter orborder length, the percentage change in size in a given quadrant, etc.are just some of the parameters that can be evaluated in each respectiveimage 604 a, 604 b.

In addition, a color, contrast, and/or a depth of each of the respectiveimages 604 a, 604 b can be determined. Balancing the color, brightness,and/or the contrast of the respective images is described below. Thefeatures that are to be evaluated can be selected by a user or can beselected automatically.

At 814, the images 604 a, 604 b are compared with respect to one anotherto identify differences between the evaluated features. For example, theareas or perimeter lengths of the respective images 604 a, 604 b can becompared. The differences may be subtle, like slight changes in color orthey may be substantial like a greatly enlarged area of the second image604 b.

At 816, any identified differences are further compared to determine ifa threshold is exceeded. For example, the threshold could be one, two,three, four, five, six, seven, eight, nine, ten, fifteen, twenty,twenty-five percent increase in the area of the second image 604 bcompared to the area of the first image 604 a. At 818, if there are nodetected differences or if the detected differences do not exceed thethreshold, then a notification is provided that no noteworthy changes ofthe image 604 b were detected. At 820, if the detected differences doexceed the threshold, then a notification is provided that noteworthychanges of the image 604 b were detected. The threshold can be a userdefined setting, a preprogrammed setting, or an automatically adjustablerange depending on the image quality and resolution, for example.

At 822, data is provided detailing the specific changes, for example,shape, color, texture, a shift in position, etc. The data and/or theresults obtained from the comparison can be made available to themedical professional in a short amount of time to enable the medicalprofessional to make a more objective, informed diagnosis and to quicklyformulate a treatment plan. Additionally or alternatively, apost-processing algorithm can be used to overlay the respective images600 a, 600 b on a screen. Color-coding, animation techniques, and othergraphic processing techniques can be used to identify areas or regionsof greatest change.

In certain embodiments, images may be captured and compared using only astandard imaging device, which includes, digital cameras, movie cameras,film cameras etc., as long as the image to be compared is at some pointmoved to a digital format thus allowing computational analysis thereon.Clearly in one embodiment an image from a standard consumer modeldigital camera is compared against a subsequent image. In suchembodiments, the computer algorithm used will perform a best fit ortransformation of the images by modifying size, angle, and brightness,to obtain the best possible fit prior to analysis for changes.Accordingly, in such embodiments users already having an archive ofolder images can compare these images. While the error rate for suchcomparison is slightly higher, the flexibility of being able to reviewolder images far exceeds the risk of a few false positive outcomes thatcan be easily discounted by the user upon further review. It should alsobe clearly understood that images taken with no focal length limiter,brightness, color, or contrast control can be compared with imageshaving such controls.

Color and/or Contrast Balancing to Detect a Suspect Area

FIGS. 10A, 10B, and 10C illustrate the color balancing of an image 900.In particular, FIG. 10A shows a digital image 900 a of a suspect area902 and a background region 904 prior to color balancing. FIG. 10B showsthe image 900 b after a filter has been applied to filter out thebackground skin region 904 based on the color, brightness, and/orcontrast of the suspect area 902 compared to the background skin region904. FIG. 10C shows the image 900 c after it has been preprocessed,which may include but is not limited the application of additionalfilters to remove other features in the image and/or the application ofa reference grid 908 over the image 900 c.

Due to slight differences in lighting and environment, the colors in animage will likely not be constant from one image to the next, eventhough steps are taken to provide constant lighting. Moreover, a skindoes not provide an adequate background for evaluating color changes ofa suspect area because the skin can change color, for example the skinmay be darker in the summer than in the winter.

One advantage of color balancing is to provide an additional parameterthat can be compared from one image to the next, for instance therespective darkness or lightness of the respective images. A secondadvantage of color balancing permits a comparison between the suspectarea and the surrounding skin as a means to more accurately detectsuspect areas 302 over a larger skin surface.

FIG. 11 shows a method 1000 of detecting suspect areas over a surface ofskin 14 by means of image filtration (i.e., color or contrastbalancing). At 1002, at least several images over a large area of skinare acquired. The images may have overlapping sections to insure thatthe entire skin area was imaged. In addition, reference markers 318 canbe placed at various locations on the imaged skin area so that anypotential suspect areas 302 that may be discovered can be relocated at alater time.

At 1004 and according to one embodiment, each image is color balancedwith respect to a reference color. In one embodiment, the referencecolor appears in the acquired image. Such a reference could includedistance measurements, contrast standards, color standards, etc. Thereference color can be a color palette of single color placed within theframe of the image when the image is acquired (FIG. 2A). The colorpalette can have a variety of shades or colors thereon. Because thereference colors are electronically isolatable, the color and/or shadingof the image can be digitally adjusted until a feature in the imageapproximately matches a certain reference color.

At 1006, after the color of the image has been adjusted, a spotdetection algorithm is used to process each of the respective images todetect any suspect areas 302 in one or more images. In one embodiment, afilter is applied to the image to make darker objects, such as a mole,stand out relative to the skin. The type of filter used will depend onthe amount of color contrast between the skin and the suspect area. Byway of example, images of a light skinned person with dark patches ontheir skin may not require filtering; whereas images of a dark skinnedperson with moderately dark patches on their skin may require a seriesof filters to achieve enough contrast between the skin and the suspectarea.

In 1008, notification of a potential suspect areas is provided to themedical professional. At this point, the medical professional couldperform a refined evaluation of any potential suspect area by takinghigher resolution images of the suspect area and comparing these imagesover time, as described in detail above. Additionally or alternatively,the medical professional can perform or recommend that a biopsy be takenof the suspect area.

Computing Systems

The computing system for performing the image comparisons may include anumber of local computers for receiving downloaded images and at leastone mainframe computer for performing the image comparisons.Alternatively, the image comparisons could be performed on the localcomputers.

The local computer typically includes a processor, memory, multiplex(“Mux”) card, video and Ethernet cards, power supply and an imageacquisition card. A number of local computers be networked together andservice a number of patient treatment facilities. The local computer cancommunicate with other local computers and/or the mainframe computerover a communications link such as a local area network (“LAN”) and/or awide area network (“WAN”). The communications link can be wired and/orwireless. The communications link can employ Internet, or World Wide Webcommunications protocols, and can take the form of a proprietaryextranet. In such instances a user could obtain images and upload theseto a web-based server that could perform all the analysis and send backto the user only the analysis or only the analysis that yielded possiblechanges. In other embodiments all algorithms could reside on thecomputer wherein the images or uploaded or on a server directlyconnected thereto. In certain embodiments, patient confidentiality ismaintained.

In certain specific embodiments a user could upload all patientinformation into a database and also have image analysis linked thereto.Accordingly, either on a remote server or housed in the users facilitycould be a computer that contains a database with a unique patientidentifier, this identifier can be used to add new images to a patientfolder and the image analysis could either be performed immediatelywhile the user waits or could be performed in the background. Subsequentto this analysis a notification could be sent via email or securedweb-access or the like that indicates the analysis has been completedand either no action is necessary or further review/action may berequired, thus indicating a change was noted between the images.

The various embodiments described above can be combined to providefurther embodiments. All of the above U.S. patents, patent applicationsand publications referred to in this specification are incorporatedherein by reference. Aspects can be modified, if necessary, to employdevices, features, and concepts of the various patents, applications andpublications to provide yet further embodiments.

These and other changes can be made in light of the above detaileddescription. In general, the terms used in the claims should not beconstrued to limit the claims to the specific embodiments disclosed inthe specification and the claims, but should be construed to cover allimaging devices, types of image formats, measuring techniques, and imagetransformation and comparison algorithms. Accordingly, the claims arenot limited by the disclosure.

1. A method of comparing at least two images, each image capturing asuspect area, the method comprising: identifying a reference item in theat least two images; measuring an attribute of the reference item in afirst image; transforming a second image based on the measured attributeof the reference item in the first image using a transformationalgorithm performed by a computing system, wherein a reference item inthe second image is transformed to correspond with an orientation andsize of the reference item in the first image; measuring an attribute ofthe suspect areas in both images; and comparing the respective measuredattributes of the respective suspect areas.
 2. The method of claim 1,further comprising: acquiring the at least two images for comparisonincludes downloading the at least two images from a computer databasewherein the first image was acquired at a first time and the secondimage was acquired at a second time.
 3. The method of claim 1 whereinmeasuring the attribute of the reference item in the first imageincludes measuring a perimeter of the reference item.
 4. The method ofclaim 1 wherein measuring the attribute of the reference item in thefirst image includes measuring a surface area of the reference item. 5.The method of claim 1 wherein transforming the second image based on themeasured attribute of the reference item in the first image includesscaling a perimeter of the reference item in the second image tosubstantially match a perimeter of the reference item in the firstimage.
 6. The method of claim 1 wherein measuring the attribute of thesuspect areas in both images includes measuring a perimeter of each ofthe respective suspect areas.
 7. The method of claim 1 wherein measuringthe attribute of the suspect areas in both images includes measuring asurface area of each of the respective suspect areas.
 8. The method ofclaim 1 wherein comparing the measured attributes of the respectivesuspect areas includes detecting a change with respect to the respectivemeasured attribute of each of the respective suspect areas in each ofthe respective images.
 9. The method of claim 1 wherein detecting achange with respect to the respective measured attribute of each of therespective suspect areas includes determining whether a perimetercorresponding to the suspect area in the first image is different than aperimeter corresponding to the suspect area in the second image.
 10. Themethod of claim 1 wherein detecting a change with respect to therespective measured attribute of each of the respective suspect areasincludes determining if a surface area corresponding to the suspect areain the first image is different than a surface area corresponding to thesuspect area in the second image.
 11. The method of claim 1 whereincomparing the respective measured attributes includes determining if achange between the respective measured attributes exceeds a threshold.12. The method of claim 11, further comprising providing an indicationthat the threshold is exceeded.
 13. The method of claim 1, whereinmeasuring the attribute of the reference item in the first imageincludes measuring a color of the reference item.
 14. The method ofclaim 1, wherein transforming the second image based on the measuredattribute of the reference item in the first image includes scaling acolor of the reference item in the second image to substantially match acolor of the reference item in the first image.
 15. The method of claim1, wherein measuring the attribute of the suspect areas in both imagesincludes measuring a color of each of the respective suspect areas. 16.The method of claim 1, wherein detecting a change with respect to therespective measured attribute of each of the respective suspect areasincludes determining whether a color corresponding to the suspect areain the first image is different than a color corresponding to thesuspect area in the second image.